School of Life Sciences, Yunnan Normal University, Kunming 650500, P.R. China.
Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Ministry of Education, Kunming 650500, P.R. China.
J Microbiol Biotechnol. 2019 Aug 28;29(8):1255-1265. doi: 10.4014/jmb.1904.04033.
To investigate the diversity of gastrointestinal microflora and lignocellulose-degrading enzymes in wild Asian elephants, three of these animals living in the same group were selected for study from the Wild Elephant Valley in the Xishuangbanna Nature Reserve of Yunnan Province, China. Fresh fecal samples from the three wild Asian elephants were analyzed by metagenomic sequencing to study the diversity of their gastrointestinal microbes and cellulolytic enzymes. There were a high abundance of and a higher abundance of hemicellulose-degrading hydrolases than cellulose-degrading hydrolases in the wild Asian elephants. Furthermore, there were a high abundance and a rich diversity of carbohydrate active enzymes (CAZymes) obtained from the gene set annotation of the three samples, with the majority of them showing low identity with the CAZy database entry. About half of the CAZymes had no species source at the phylum or genus level. These indicated that the wild Asian elephants might possess greater ability to digest hemicellulose than cellulose to provide energy, and moreover, the gastrointestinal tracts of these pachyderms might be a potential source of novel efficient lignocellulose-degrading enzymes. Therefore, the exploitation and utilization of these enzyme resources could help us to alleviate the current energy crisis and ensure food security.
为了研究野生亚洲象胃肠道微生物群和木质纤维素降解酶的多样性，我们从中国云南西双版纳自然保护区的野象谷中选择了同一象群中的 3 头亚洲象进行研究。通过宏基因组测序分析了这 3 头野生亚洲象的新鲜粪便样本，以研究其胃肠道微生物和纤维素酶的多样性。与纤维素降解酶相比，野生亚洲象中木质素降解水解酶的丰度更高。此外，从 3 个样本的基因集注释中获得了大量的碳水化合物活性酶（CAZymes），具有丰富的多样性，其中大多数与 CAZy 数据库条目具有较低的同一性。约一半的 CAZymes 在门或属水平上没有物种来源。这表明野生亚洲象可能具有比纤维素更强的消化木质素的能力，以提供能量，此外，这些厚皮动物的胃肠道可能是新型高效木质纤维素降解酶的潜在来源。因此，这些酶资源的开发和利用可以帮助我们缓解当前的能源危机，确保粮食安全。
